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std::stoul, std::stoull

From cppreference.com
< cpp‎ | string‎ | basic string
 
 
 
std::basic_string
 
Defined in header <string>
unsigned long      stoul( const std::string& str, std::size_t* pos = 0, int base = 10 );
unsigned long      stoul( const std::wstring& str, std::size_t* pos = 0, int base = 10 );
(1) (since C++11)
unsigned long long stoull( const std::string& str, std::size_t* pos = 0, int base = 10 );
unsigned long long stoull( const std::wstring& str, std::size_t* pos = 0, int base = 10 );
(2) (since C++11)

Interprets an unsigned integer value in the string str.

1) calls std::strtoul(str.c_str(), &ptr, base) or std::wcstoul(str.c_str(), &ptr, base)
2) calls std::strtoull(str.c_str(), &ptr, base) or std::wcstoull(str.c_str(), &ptr, base)

Function discards any whitespace characters (as identified by calling isspace()) until first non-whitespace character is found. Then it takes as many characters as possible to form a valid base-n (where n=base) unsigned integer number representation and converts them to an integer value. The valid unsigned integer value consists of the following parts:

  • (optional) prefix (0) indicating octal base (applies only when the base is 8 or 0)
  • (optional) prefix (0x or 0X) indicating hexadecimal base (applies only when the base is 16 or 0)
  • a sequence of digits

The set of valid digits for base-2 integer is 01, for base-3 integer is 012, and so on. For bases larger than 10, valid digits include alphabetic characters, starting from Aa for base-11 integer, to Zz for base-36 integer. The case of the characters is ignored.

Additional numeric formats may be accepted by the currently installed C locale.

If the value of base is 0, the numeric base is auto-detected: if the prefix is 0, the base is octal, if the prefix is 0x or 0X, the base is hexadecimal, otherwise the base is decimal.

If pos is passed a value other than 0 or nullptr, then a pointer ptr, internal to the conversion functions, will receive the address of the first unconverted character, and the index of that character will be calculated and stored in *pos.

Contents

[edit] Parameters

str - the string to convert
pos - address of an integer to store the index of the first unconverted character
base - the number base

[edit] Return value

The string converted to the specified unsigned integer type.

[edit] Exceptions

  • std::invalid_argument if no conversion could be performed
  • std::out_of_range if the converted value would fall out of the range of the result type or if the underlying function (std::strtoul or std::strtoull) sets errno to ERANGE.

[edit] See also

(C++11)(C++11)(C++11)
converts a string to a signed integer
(function) [edit]
(C++11)(C++11)(C++11)
converts a string to a floating point value
(function) [edit]